JP2002116167A - Measuring instrument and measuring method for thermal conductivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal conductivity measuring instrument capable of measuring the thermal conductivity of a body to be tested in the direction of its thickness and capable of accurately finding the thermal conductivity of the body to be tested in directions of its plane without cutting the body into a rectangular shape in the case of thermal conductivity measurement of an anisotropic material, and to provide a thermal conductivity measuring method using the same. SOLUTION: This thermal conductivity measuring instrument 10 has a heating means 5 for causing heat to flow into a surface of a tested body 1a on one side, a heat radiating means 6 for causing heat to flow out of a surface of a tested body 1b on the other side, tested-body surface part measuring means 7 and 8 for measuring the temperatures of the two surfaces of the tested bodies 1a and 1b, a linear heating body 3 disposed between the tested bodies 1a and 1b to propagate heat into the tested bodies, and a temperature measuring means 4 for measuring temperatures within the tested bodies and in the proximity of the heating body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal conductivity measuring device for measuring the thermal conductivity of a heat insulating material such as a heat-resistant material or a refractory material.

[0002]

2. Description of the Related Art Generally, the thermal conductivity of a substance is measured by flowing heat through the substance (test body). As the measuring method, there are a flat plate direct method (GHP method), a flat plate heat flow meter method, a periodic heating method, a fine wire heating method, and the like. The flat plate direct method and the flat plate heat flow meter method measure the thermal conductivity in the thickness direction of a flat (rectangular) specimen. One surface of the specimen is set to a high temperature and the other is set to a low temperature. Then, a predetermined amount of heat flows from one surface at a high temperature (heating side) to another surface at a low temperature (low temperature side), that is, in the thickness direction. In this case, the following equation: Q = (λ / d) (θ _H −θ _L ) (I) (θ _H : temperature on the heating side, θ _L : temperature on the heat radiation side, d: thickness of test specimen, Q: the unit area flowing through the test body, the amount of heat per unit time, and λ: the thermal conductivity). Here, the Q is measured from the calorific value of the heater that heats the high temperature side in the flat plate direct method, and is measured by measuring the electromotive force of the heat flow meter in the flat plate heat flow meter method. Further, θ _H and θ _L can be measured by a thermocouple, and if the thickness d of the specimen is known in advance, the thermal conductivity λ can be calculated. Such a method and apparatus for measuring the thermal conductivity λ by the flat plate direct method and the flat plate heat flow meter method are described in detail in JIS A 1412 (a method for measuring the thermal conductivity and thermal resistance of a heat insulating material).

[0003] The periodic heating method is a method for measuring the thermal diffusivity, and there are two methods, a phase difference method and an amplitude method. The phase difference method is a method in which a temperature wave is applied to one surface, and the time delay when the wave propagates inside the specimen, that is, the thermal diffusivity is obtained from the phase difference. The amplitude method is a method in which the temperature wave propagates. This is a method of calculating the thermal diffusivity from the attenuation rate at the time. In either method, the thermal conductivity is determined by multiplying the specific heat and the density by the thermal diffusivity. The method and the measuring device for measuring the thermal conductivity λ by such a periodic heating method are, for example, thermophysical properties.
13, Vol. 4, No. 4 (1999), pp. 264-270.

[0004] The fine wire heating method is also called a transient hot wire method,
A linear heating element such as a thin wire or a heating wire such that the size of the test piece can be regarded as infinite is heated, for example, by a power supply for a predetermined time, and the thermal conductivity is determined from the temperature rise and the calorific value of the linear heating element. It is a method of measuring. When heating the linear heating element, the heat generated from the linear heating element propagates concentrically,
The amount of heat generated by the linear heating element per unit time is Q ′
When the temperature at times t ₁ and t ₂ after the start of heat generation, measured by a temperature measuring means such as a thermocouple, is θ ₁ and θ ₂ , respectively, and the length of the heating wire is L, the test specimen Is the following equation: λ = (Q ′ / 4πL) × ｛log (t ₂ / t ₁ ) /
(Θ ₂ −θ ₁ )｝ holds, whereby the thermal conductivity λ can be obtained. Although the fine wire heating method is suitable for measuring isotropic materials such as urethane and calcium silicate heat insulating materials, in the measurement of anisotropic materials, heat from a linear heating element does not propagate concentrically. , The above equation does not hold, and accurate measurement cannot be performed.

[0005] Test specimens whose thermal conductivity is measured include anisotropic materials such as fibrous heat insulating materials in addition to isotropic materials. Understanding the thermal conductivity of anisotropic materials is very important in material development, and the thermal conductivity of anisotropic materials can be measured by the flat plate direct method (GHP method), flat plate heat flow meter method, and periodic heating method. It is measured by such a method. However, these measuring methods can measure the thermal conductivity in the heat flow direction (thickness direction of the specimen), but the thermal conductivity in the plane direction perpendicular to the thickness direction of the specimen. Can not be measured.

Therefore, in order to measure the thermal conductivity of the anisotropic material in the plane direction, after measuring the thermal conductivity in the thickness direction of the specimen, the specimen is cut into strips and rotated by 90 degrees. It is necessary to rearrange the test specimens so that the plane direction becomes the thickness direction, and to measure the thermal conductivity in the thickness direction of the rearranged test specimen.

[0007]

However, a method for preparing a new test piece by cutting the test piece into a strip shape has a problem in that a gap is formed between the cut surfaces, or the height of each strip after being rotated is reduced. There is a risk that there is a possibility of unevenness or unevenness on the surface of the test piece, and there is a problem that skill is required to prepare a test piece that can be measured with high accuracy. for that reason,
There is a need for a thermal conductivity measuring device and a method for measuring the thermal conductivity that can determine the thermal conductivity in the thickness direction and the planar direction of a test body without cutting out the test body.

Accordingly, an object of the present invention is to measure the thermal conductivity of an anisotropic material in the thickness direction of a specimen and to cut the specimen into strips without measuring the thermal conductivity.
It is an object of the present invention to provide a thermal conductivity measuring device capable of accurately determining a thermal conductivity in a plane direction of a test body and a method for measuring thermal conductivity using the same.

[0009]

Under such circumstances, the present inventors have conducted intensive studies and as a result, among anisotropic materials,
As long as the material has planar orientation, the theoretical equation of heat propagation by the fine wire heating method can be applied, and the correction formula derived therefrom can be used.Therefore, the heating element of the fine wire heating method and the flat plate direct The inventors have found that if a heater or thermocouple, etc., is used for the method or the like, the thermal conductivity can be measured in the plane direction as well as in the depth direction of the specimen without moving the specimen in the apparatus, and completed the present invention. I came to.

That is, a first aspect of the present invention is to provide a heating means for supplying heat to one surface of a test body or for supplying a temperature wave, and for allowing heat to flow out from the other surface of the test body. Or a heat radiating means for absorbing a temperature wave, and a temperature of both surfaces of the specimen, a heat quantity passing through the specimen, or a heat propagation phase difference between both surfaces of the specimen or an attenuation of a temperature wave amplitude between both surfaces of the specimen. A test piece surface measuring means for measuring the rate, a linear heating element arranged in the test piece and transmitting heat to the test piece, and measuring a temperature in the test piece and in the vicinity of the linear heating element. The present invention provides a thermal conductivity measuring device having a temperature measuring means.

According to a second aspect of the present invention, there is provided a method for measuring thermal conductivity using the thermal conductivity measuring device, wherein heat is supplied to the specimen by the heating means, The first measurement of supplying heat and causing heat to flow out of the specimen by the heat radiating means or flowing heat into the specimen by absorbing a temperature wave to measure the thermal conductivity, and disposing in the specimen Performing a second measurement of measuring the thermal conductivity by measuring the temperature in the test body and in the vicinity of the linear heating element by the temperature measuring means,
The switching from the first measurement to the second measurement, or the switching from the second measurement to the first measurement, provides a method for measuring the thermal conductivity that is performed without moving the test body.

According to a third aspect of the present invention, the test object is a test object having a planar orientation, wherein the thermal conductivity λ _y of the first measurement result and the thermal conductivity λ _h of the second measurement result are determined. The following formula (1); λ _x = λ _h ² / λ _y (1) is provided to provide a method of measuring the thermal conductivity to obtain the thermal conductivity λ _x in the planar direction of the test body.

According to a fourth aspect of the present invention, the measuring method of the first measurement is any one of a periodic heating method, a flat plate direct method, and a flat plate heat flow meter method. An object of the present invention is to provide a method for measuring thermal conductivity, which is a thin wire heating method.
In the present invention, the non-stationary hot wire method is also included in the thin wire heating method.

[0014]

FIG. 1 shows a thermal conductivity measuring apparatus according to the present invention.
This will be described with reference to FIGS. FIG. 1 is a schematic diagram of a thermal conductivity measuring device according to the present embodiment, FIG. 2 is a schematic diagram of a core portion of a thermal conductivity measuring device for performing measurements by a fine wire heating method and a periodic heating method, and FIG. FIG. 4 is a diagram for explaining a calculation formula applied to a material, FIG. 4 is a schematic diagram of a core portion of a thermal conductivity measuring device for performing measurement by a thin wire heating method and a flat plate direct method, and FIG. FIG. 6 is a schematic view of a core part of a thermal conductivity measuring device for performing measurement by a thin wire heating method and a flat plate heat flow meter method.

The thermal conductivity measuring device 10 is configured to determine whether heat flows into one surface of the specimen 1 or heating means 5 for supplying a temperature wave, and heat flows out from the other surface of the specimen 1. Alternatively, the heat radiating means 6 that absorbs the temperature wave and the temperature of both surfaces of the specimen 1, the amount of heat passing through the specimen, or the heat propagation phase difference between both surfaces of the specimen or the amplitude of the temperature wave between both surfaces of the specimen Specimen surface portion measuring means 7 and 8 for measuring the attenuation rate, linear heating element 3 arranged in specimen 1 and transmitting heat to specimen 1, and linear heating element 3 in specimen 1 and linear heating element 3 And a temperature measuring means 4 for measuring the temperature in the vicinity of the test piece. Further, the side face of the test piece is provided with a cylindrical heater 2 for the purpose of preventing heat dissipation from the side face of the test piece 1. And heating means 5, heat radiation means 6,
The linear heating element 3 and the cylindrical heater 2 are electrically connected to a function generator 11 as a power supply and a temperature controller 12. Further, a temperature controller 12, a test body surface portion measuring means 7,
8 and the temperature measuring means 4 are electrically connected to a computer 15 via a scanner 13 and a digital multimeter 14, which take in data, perform processing, and transfer heat of the specimen 1 to an output device of the computer 15. The rate is displayed.

Next, a thermal conductivity measuring apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 2 is a schematic view of a core 20a of a thermal conductivity measuring device using a periodic heating method and a fine wire heating method. A test specimen 1a of 150 × 150 × 25 mmt and a test specimen 1b of the same dimensions are superimposed on a nichrome wire 3 having a diameter of 0.3 × 150 mm while sandwiching a K-type thermocouple 4 having a diameter of 0.1 mm to form a test specimen 1. At this time, the nichrome wire 3 traverses substantially the center of the test body 1, and the temperature measuring portion of the thermocouple 4 is near the center of the nichrome wire 3. Further, the specimen 1 is sandwiched between a heater 5 of 150 × 100 × 30 mmt and a heater 6 of the same size from above and below. At this time, a K-type thermocouple 7 having a diameter of 0.1 mm is sandwiched between the specimen 1 a and the heater 5. A K-type thermocouple 8 having a diameter of 0.1 mm is sandwiched between the test piece 1 b and the heater 6. Core 20
Structures other than a are the same as those in FIG.

The test body 1a and the test body 1b are a kind of anisotropic material, and if the material has planar orientation, the effect of the present invention is particularly remarkable. As the anisotropic material having planar orientation, for example, a material in which fibers and the like are arranged in a certain plane in a plane direction at a high rate, but are randomly distributed without orientation in a direction perpendicular to the plane, And a uniaxially oriented material such as a so-called regularly incense stick in which most fibers and the like are arranged in a certain direction. Specific examples of the material having planar orientation include, for example, an inorganic heat insulating material made of alumina silica fiber, rock wool and glass wool, a laminate made of organic fibers such as nylon and carbon fibers, and a heat insulating material. The orientation of these planar anisotropic materials can be easily confirmed by SEM (electron microscope), optical microscope, or the like.
Further, when a material having planar orientation is used as the test specimen, the orientation direction of the fiber or the like or a direction perpendicular to the orientation direction may be set as the plane of the test specimen.

First, the thermal conductivity of the test body 11 is measured by the periodic heating method using the thermal conductivity measuring apparatus according to the first embodiment (first measurement). In the measurement, the surface temperature of the specimen 1a is periodically changed by applying a periodic voltage to the heater 5, and the surface temperature of the specimen 1b is controlled to be constant by the heater 6. The temperature wave is measured by the thermocouples 7 and 8, and the time difference (phase difference) or the attenuation ratio of the amplitude is measured to determine the thermal diffusivity. Thereafter, it may be calculated thermal conductivity lambda _y in the thickness direction of the test specimen by multiplying the specific heat and density to the thermal diffusivity.

Next, the thermal conductivity of the test piece 1 is measured by the thin wire heating method (second measurement). First, the specimens 1a and 1b are brought to a predetermined temperature by the cylindrical heater 2 and the heaters 5 and 6,
Specimens without temperature gradient shall be used. Next, a constant current is passed through the nichrome wire 3 and the heating temperature rise after a predetermined time is, for example,
Two or more points were measured after 0.5 minutes and 5 minutes, and the relational expression of time and temperature rise: λ = (Q ′ / 4πL) × ｛log (t ₂ / t ₁ ) / (
θ ₂ −θ ₁ )｝ (where the symbols have the same meanings as described above), and the thermal conductivity λ _h is determined.

The thermal conductivity λ _y and the thermal conductivity λ _h obtained by the above method are substituted into the following equation (1); λ _x = λ _h ² / λ _y (1) Specimen 1 within 20a
Without moving the 1, it is possible to obtain a planar direction of the thermal conductivity lambda _x of the specimen 11. The above (1) is derived as follows.

FIG. 3A shows an isotropic specimen C by a thin line.
Heat flow in a cross section perpendicular to the thin wire when heated
The outline of the dispersion is shown, and (B) is a thin line of the specimen D having the planar orientation
In a cross section perpendicular to the fine wire when heated by heating
An outline of flow diffusion is shown. In the figure, the y-axis is the thickness direction of the specimen.
And the x-axis indicates the plane direction of the test specimen. In FIG. 3 (A)
As shown, in the cross section of the isotropic specimen C, a thin line 3
Heat flows out of the test specimen concentrically with the fine wire 3
It spreads. On the other hand, as shown in FIG.
In the cross section of the directional specimen D, the heat flow emerging from the fine wire is
The speed of propagation in the plane direction is different from the speed of propagation in the thickness direction.
Therefore, the light diffuses in an elliptical shape as shown in the figure. Planar orientation
Focusing on the thermal diffusivity and thermal diffusion area of the test specimen of
Thermal diffusivity κ of the specimen measured by heating method_hAnd the period
It can be measured by the heating method, flat plate heating method or flat plate heat flow meter method.
Thermal diffusivity κ in the thickness direction of the specimen_yAnd asked
Thermal diffusivity κ of the specimen to be tested_xIntroduce mutual relationships with
The thermal conductivity λ _h, Λ_y, And λ_xThe relationship
Lead.

FIG. 3B shows that the planar arrangement by the fine wire heating method is used.
In the measurement of the thermal conductivity of the test specimen D for a certain time t
The heat diffusion distance in the thickness direction is a, and the heat diffusion distance in the plane direction is
Assuming that the separation is b, the heat diffusion area S at time t is S = πab (2) Therefore, the planar orientation measured by the fine wire heating method
Thermal diffusivity κ of specimen D _hIs κ_h= Πab / t (3) On the other hand, the same
Thermal diffusivity κ_yIsotropic specimen C having fine wire
Is measured, the thermal diffusivity of the specimen C is κ_yWhen
Become equal. In this case, the heat flow from the hot wire is concentric
And the thermal diffusion distance at a certain time t becomes a
The area S diffused at time t_yIs S_y= Πa^Two (4) Therefore, the thermal diffusivity of the specimen C, that is, the average
Thermal diffusivity κ in the thickness direction of plane orientation specimen D_yIs the following calculation
Equation (5); κ_y= Πa^Two/ T (5). On the other hand, the same
Thermal diffusivity κ_xIsotropic test specimens with fine wire
When measured from the above, the thermal diffusivity of the specimen is κ_xEqual
It becomes. In this case, the heat flow from the hot wire expands concentrically.
And the heat diffusion distance at a certain time t is b,
Area S diffused at time t_xIs S_x= Πb^Two (6) Therefore, the thermal diffusivity of the specimen,
Thermal diffusivity κ in the plane direction of orientation specimen D_xIs the following formula
(7); κ_x= Πb^Two/ T (7). From the above equations (3), (5) and (7)
When erasing a and b, κ_h= (Κ_y× κ_x)^1/2 (8) Is thermal diffusivity and thermal conductivity proportional?
Were determined by the fine wire heating method in the plane orientation test specimen D.
Thermal conductivity λ_h, In the plane orientation test specimen D,
Thermal conductivity λ_yTo the plane orientation specimen D to be obtained.
The thermal conductivity in the plane direction_xThen λ_h= (Λ_y
× λ_x)^1/2And the above-mentioned calculation formula (1) is obtained. Obedience
Λ_hMeasure the flat plate direct method, flat
Λ by plate heat flow meter method or periodic heating method_yIf you measure
From the above formula, the thermal conductivity in the plane direction λ _xCan ask
it can.

In the first embodiment, a first measurement for measuring the thermal conductivity of the specimen 1 by the periodic heating method and a second measurement for measuring the thermal conductivity of the specimen 1 by the thin wire heating method are performed. The order is not particularly limited, and the first measurement may be performed after the second measurement is performed in addition to the above. The test body may be a single test body or a plurality of test bodies. If the test piece is a single test piece, make a hole through the test piece near the center in the thickness direction of the test piece, pass a hot wire through the hole, and from a direction about 90 degrees to the hot wire to the vicinity of the hot wire. A thermocouple may be inserted into the drilled hole. The angle of the thermocouple with respect to the heat wire is not particularly limited, and it is possible to pass the heat wire and the thermocouple through the same hole as long as the thermocouple has electrical insulation. Further, when manufacturing the test piece, the heating wire and the thermocouple may be embedded in advance substantially perpendicular to the plane direction of the test piece. When three specimens are used, two adjacent specimens are selected, and a heating wire and a thermocouple may be inserted between the two specimens in the same manner as described above.

Next, a thermal conductivity measuring apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 2 is a schematic view of a core 20b of a thermal conductivity measuring device by a flat plate direct method and a thin wire heating method. A specimen 1a of 300 × 300 × 25 mmt and a specimen 1b of the same dimensions are stacked with a nichrome wire 3 having a diameter of 0.3 × 300 mm and a K-type thermocouple 4 having a diameter of 0.1 mm to form a specimen 1. At this time, the nichrome wire 3 traverses substantially the center of the test body 1, and the temperature measuring portion of the thermocouple 4 is near the center of the nichrome wire 3. Further, the specimen 1 has a main heater 5a of 150 × 150 × 15 mmt from above and
300 × 15mmt central part 150 × 150 × 15mmt cut-out protective heater 5b and 300 × 300 × 15mmt heater 6
At this time, a K-type thermocouple 7 having a diameter of 0.1 mm is sandwiched between the test body 1a and the heater 5a, and a K-type thermocouple 8 having a diameter of 0.1 mm is sandwiched between the test body 1b and the heater 6a. Heater 5
A heater 5c of 300.times.300.times.15 mmt is installed above the a and 5b with a heat insulating material 9 of 300.times.300.times.25 mmt.
Other configurations other than the core portion 20b are the same as those in FIG. 1, and a description thereof will be omitted.

Next, using the thermal conductivity measuring apparatus of the second embodiment, the thermal conductivity of the test piece 1 is measured by the flat plate direct method (first measurement). First, the power of each heater is turned on. The main heater 5a and the protection heater 5b supply a heat flow into the specimen 1. The radiation side heater 6a allows the radiation side heater 6
The amount of heat generated by a and the amount of heat absorbed by the heat radiating member arranged around the heat radiating side heater 6a are balanced. Thereby, the heat radiation member can function as a constant temperature body. As shown in FIG. 5, the heat flow propagating through the test piece 1 having no temperature gradient in the x direction is absorbed by the refrigerant of the heat dissipating member functioning as a constant temperature body. The measurement is performed by measuring the temperatures on the heating side and the heat radiation side of the test body with the thermocouples 7 and 8, and measuring the calorific value Q of the heating side main heater 5a with a wattmeter or the like. Thermal conductivity lambda _y is determined by the equation (I).

Next, the thin wire heating method to be measured is performed in the same manner as in the first embodiment, and the thermal conductivity λ _h and λ _x are obtained. According to the second embodiment, similarly to the first embodiment, the test piece having planar orientation is not cut into strips, and the heat conductivity in the horizontal direction is obtained together with the heat conductivity in the depth direction. The conductivity can be easily obtained.

A thermal conductivity measuring device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic view of the core 20c of the thermal conductivity measuring device based on the flat plate heat flow method and the thin wire heating method. 6, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.
The points different from the above will be described. That is, in FIG.
The difference is that the heater 5d is mounted on the upper part of the test body 1a, and the heat flow meter 16 is provided between the heater 5d and the test body 1a, and the heat flow meter 17 is provided between the test body 1b and the heat radiating heater 6a.
There is a point to be attached.

In order to measure the thermal conductivity of the specimen 1 by the flat plate heat flow meter method, first, the temperatures of the heating side and the heat radiation side of the specimen are measured by thermocouples 7 and 8 (first measurement). By measuring the amount of heat passing through the heat flowmeters 16 and 17. Thermal conductivity lambda _y is determined by the above equation (I). Next, the thin wire heating method to be measured is performed in the same manner as in the first embodiment, and the thermal conductivities λ _h and λ _x are obtained.
According to the third embodiment, similarly to the first embodiment, the test piece having planar orientation is not cut into strips, and the heat conductivity in the horizontal direction is obtained together with the heat conductivity in the depth direction. The conductivity can be easily obtained.

[0029]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but these are merely examples and do not limit the present invention.

Example 1 A thermal conductivity measuring device having the structure shown in FIGS. 1 and 2 was used. The specimen was an alumina silica blanket (bulk density 1
A fibrous heat insulating material having a planar orientation of 30 kg / m ³ ) was used. Five points were taken in the measurement temperature range of about -130 ° C to room temperature. At each temperature, first, the thermal conductivity λ _h of the specimen was measured by the fine wire heating method, and then the periodic heating was performed without moving the specimen. the thermal conductivities were measured for λ _y by law. These measurement methods were performed by the method described in the first embodiment. Then, λ _h and λ _y are calculated by the above equation (1).
And λ _{x in} the plane direction of the specimen was determined. λ _h , λ
FIG. 7 shows the results of _y and λ _x obtained by the calculation formula.

Reference Example 1 A thermal conductivity measuring device having the structure shown in FIGS. 1 and 2 was used. The test body used was the one in Example 1. The test specimen of Example 1 was cut into a strip shape, rotated by 90 degrees in the apparatus, arranged so that the plane direction became the depth direction, and the thermal conductivity in the thickness direction of the arranged test specimen (Example) It was measured applicable) in the direction of the plane of the thermal conductivity lambda _x 1 of the specimen. The test pieces were carefully cut out and arranged in a strip shape so as to reduce measurement errors as much as possible. The results are shown in FIG.

As is clear from FIG. 7, the value of λ _x obtained in Example 1 is in good agreement with the value of λ _x measured in Reference Example 1, and the value of λ _x was measured by the thermal conductivity measuring apparatus of the present invention. It can be seen that the thermal conductivity in the thickness direction of the specimen can be measured without moving the specimen, and the thermal conductivity in the plane direction of the specimen can be accurately obtained.

[0033]

According to the thermal conductivity measuring apparatus and the measuring method of the present invention, in the thermal conductivity measurement of a specimen having a planar orientation, the thermal conductivity in the thickness direction of the specimen is measured and the specimen is measured. The thermal conductivity in the plane direction of the test specimen can be accurately obtained without moving.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a thermal conductivity measuring device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a core part of a thermal conductivity measuring device for performing measurement by a thin wire heating method and a periodic heating method.

FIG. 3 is a diagram for explaining a calculation formula applied to a planar orientation material.

FIG. 4 is a schematic view of a core part of a thermal conductivity measuring device for performing measurement by a thin wire heating method and a flat plate direct method.

FIG. 5 is a view showing a vertical cross section at the center of FIG. 4;

FIG. 6 is a schematic diagram of a core portion of a thermal conductivity measuring device for performing measurement by a thin wire heating method and a flat plate heat flow meter method.

FIG. 7 is a diagram showing the relationship between the thermal conductivity in the plane direction of the test piece and the average temperature of the test piece obtained by the thermal conductivity measuring device of the present invention.

[Explanation of symbols]

 1, 1a, 1b test body 2 cylindrical heater 3 linear heating element (nichrome wire) 4 temperature measuring means (thermocouple) 5 heating means (heater) 6 heat radiating means (heater) 7, 8 test body surface measuring means (nichrome) Line) 10 thermal conductivity measuring device 11 function generator 12 temperature controller 13 scanner 14 digital multimeter 15 computer

Claims (4)

[Claims] 1. A method according to claim 1, wherein heat is applied to one surface of the specimen.
Or a heating means for supplying a temperature wave, or a heat radiating means for allowing heat to flow out from the other surface of the test piece or absorbing the temperature wave, and a temperature of both surfaces of the test piece, the heat quantity passing through the test piece,
Or, a specimen surface portion measuring means for measuring a heat propagation phase difference between both surfaces of the specimen or an attenuation rate of a temperature wave amplitude between both surfaces of the specimen, and disposed in the specimen, and heat is applied to the specimen. And a temperature measuring means for measuring the temperature in the test body and in the vicinity of the linear heating element. 2. A method for measuring thermal conductivity using the thermal conductivity measuring device according to claim 1, wherein heat is supplied to the test piece by the heating means or a temperature wave is supplied. A first measurement in which heat is caused to flow out of the test piece by the heat radiating means or a heat wave is caused to flow through the test piece by absorbing a temperature wave to measure thermal conductivity; and a linear heat generation arranged in the test piece. A second measurement of measuring the thermal conductivity by heating the body and measuring the temperature in the test body and in the vicinity of the linear heating element by the temperature measuring means, and performing the second measurement from the first measurement Switching from the second measurement to the first measurement without moving the test specimen. 3. The test piece is a test piece having planar orientation, and the thermal conductivity λ _y of the first measurement result and the thermal conductivity λ _h of the second measurement result are represented by the following formula (1): λ _x = by substituting ^{_{λ h 2 / λ y (1}} ), method of measuring the thermal conductivity of claim 2, wherein the determination of the thermal conductivity lambda _x in the plane direction of the specimen. 4. The method of measuring the first measurement is a periodic heating method,
The method for measuring thermal conductivity according to claim 2 or 3, wherein the method is one of a flat plate direct method and a flat plate heat flow meter method, and the measuring method of the second measurement is a thin wire heating method.